Plumbing Connection Summer 2016

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PLUMBING CONNECTION

SUMMER 2016

PRESSURE REGULATING VALVES IN

MULTISTOREY APPLICATIONS

ressure Reducing Valves (PRVs) are commonly used

in multistorey buildings for cold water and water

potable supply and for cold water for fire services.

They generally fall into two design categories: Direct Acting

and Pilot Operated PRVs.

Each of these valves has particular characteristics

that are ideally suited to specific applications. A better

understanding of these design features will ensure that you

select the optimum PRV for individual applications or overall

pipeline systems.

In the first instance, it’s important to know what a PRV

is, and what it does. While it would seem obvious, there is a

fair amount of uncertainty and ambiguity surrounding PRV

design and functionality.

In general terms, a PRV, which can also be referred to as a

Pressure Regulating Valve, is defined as a valve that reduces

upstream (inlet) pressure down to a lower downstream

(outlet) set pressure, irrespective of the flows passing

through the valve.

The first type of PRV we’ll analyse is the Direct Acting

Pressure Reducing Valve.

There are many brands available in Australia. The principle

of operation is generally consistent and applies to all of

them. Their function is as follows:

∫ From the diagram above, you can see that there is an

adjustment spring, adjustment bolt, diaphragm, seat and

a sealing disk.

∫ The downstream pressure is set using the adjustment

bolt, which applies tension to the PRV spring.

∫ The spring applies a force to the PRV diaphragm, which is

opposing the force created by the pressure underneath

the diaphragm coming from the water downstream of the

valve.

RUSS DUNNE

OF BERMAD WATER TECHNOLOGIES TAKES A LOOK AT THE TWO MAIN TYPES OF PRESSURE

REGULATING VALVES USED IN MULTISTOREY BUILDINGS AND THE VARIOUS BENEFITS AND FEATURES OF EACH.

Pressure Regulating Valves act to reduce upstream (inlet) pressure down to a lower downstream (outlet) set pressure,

irrespective of the flows passing through the valve.

VALVE CONTROL

RUSS DUNNE